In an increasingly networked world, more and more traffic, such as data, voice, and video, is transmitted over public and proprietary networks. When routing traffic through a network, it is desirable to be able to monitor and control connections between nodes in order to dynamically assess network health and to maintain a desired quality of service (QoS) for the network. Circuit-based transport protocols, such as the synchronous optical network (SONET) standard, often include operations, administration, and management (OAM) information appended to or within headers or trailers of payload-carrying frames (e.g., asynchronous transfer mode (ATM) frames) being transported over a network. OAM information is appended to payload-carrying frames for the purpose of detecting certain network conditions, such as congestion, delay, jitter (e.g., mistimed or out-of-sync frames), out-of-order frames, and dropped frames, etc. When certain conditions are detected, OAM notifications are sent that enable network devices to perform rerouting operations and/or network administrators to conduct troubleshooting operations, to implement protection measures, and/or to perform repairs.
In packet-switched networks, OAM information is often inserted into the network as stand alone packets (e.g., sometimes referred to as “probes”), that are separate from payload-carrying packets (e.g., client packets). Thus, stand alone OAM packets transported within a packet-switched network provide similar monitoring and control information as OAM information appended to payload-carrying frames transported within circuit-switched networks. One disadvantage of stand alone OAM packets, however, is that client packets (e.g., unicast or multicast client packets) may experience different network conditions than stand alone OAM packets and, thus, stand alone OAM packets provide only an approximation of the actual network conditions experienced by client packets. Another disadvantage is that stand alone OAM packets add additional bandwidth overhead to the packet-switched network and complicate the packet accounting of the network (e.g., packets or bytes sent/received, etc.).